In the paper the guidance algorithm based on the modified proportional guidance method is considered
It is supposed that the interceptor has a control system with four engines with the pulse control, located symmetrically relative to the interceptor axis. Characteristic velocity resource and the maximum acceleration are limited.
Interception is carried out under the following scheme:
Acceleration the interceptor to the prospective engagement point and its further passive exoatmospheric ballistic-trajectory flight.
Detection of the target by optical target seeker and switching the interceptor to the guidance mode with use of measured angular coordinates of object
Interceptor control is realized on the base of proportional approach method, which minimizes angular drift rate of target from target seeker field of view. Angular drift rate estimation is calculated using the trajectory state vector estimation which in order is calculated using linearized Kalman filter.
The interceptor has information from the external source that in given time trub the ballistic object will be situated at the given height. Also it has the information about the estimated object state vector for this height and vector’s covariance matrix. Based on this data and knowledge of self and object’s motion equations, the interceptor chooses launch time ts in the way that provide interceptor getting to engagement point in the time trub without additional control. The interceptor extrapolates object’s state vector and covariance matrix in accordance with motion equation. The interceptor starts movement in the time ts and starting from the moment of achieving of required distance to the object turns on the measuring line and self-control. It should be noted that from the moment measuring line starts work, object state vector is estimated with Kalman filter, and control matrixes are calculated for each moment of time in accordance with object and interceptor coordinates.
In the paper the guidance algorithm based on the information from target seeker, measuring angular coordinate of the object is proposed. Results of modeling of common interception scenarios with proposed interception behavior algorithm are presented. Dependency of engagement probability from error variance of angular coordinate measuring by target seeker is found.